Comfortable and user friendly office equipment which can be readily adapted to a user's individual needs is a prerequisite for creating an office work environment conducive to maximum productivity. Office chairs are an integral part of any office environment and chairs having features which can be adjusted to meet a user's posture requirements clearly play a pivotal role in contributing to a user's comfort level. In particular, chairs having seat tilt mechanisms are well known and employ the user's weight to move the chair seat against a spring bias.
These tilt mechanisms include a brake to lock the seat in place. The brake includes a bracket mounted in the tilt mechanism housing into which the seat spindle is inserted. At one end of the bracket there is attached a plurality of longitudinal, flat steel arms each having a hole through the end spaced from the bracket. A plurality of separate, longitudinal and flat steel arms having holes in each end thereof are mounted in the tilt mechanism bracket so that one end of the separate steel flats are interleaved between the ends of the arms attached to the bracket. The holes in the ends of the separate arms are in registration with the holes in the arms attached to the bracket. The separate arms are mounted in the housing by a pivot rod extending between the housing side walls and transversely through the holes in the other ends of the arms. Both sets of steel arms have a surface coating applied thereto for protection. The brake includes a locking arm pivotally connected to a bolt which extends through the registered holes in the two sets of steel arms. The locking arm is connected to the bolt in such a way that pivoting the locking arm with respect to the bolt causes the bolt to move which acts to compress the two sets of arms together adjacent the holes in the arms. When the arms are compressed together, the spindle bracket, and hence the chair seat, is locked in position against pivotal movement.
Drawbacks to these devices are that the plurality of bracket arms are separately welded to the frame in parallel. This is a time consuming procedure to individually align and weld the arms to the frame. The resulting bracket and arm combination is fairly heavy in addition to being expensive to fabricate since separate, multiple welding steps are required. Further, the brake mechanism employs compression to squeeze the two sets of arms together so that during tilting movement of the seat the resulting friction between these two components causes the coating layer of each arm to be worn off thereby producing an unsightly fine powder.
Accordingly, it would be advantageous to provide an improved brake mechanism for a chair seat tilt mechanism which is lighter than the prior art devices, more economical to manufacture and which is less prone to producing an unsightly residue when in use.